# Copyright 2009-2011 Ram Rachum.
# This program is distributed under the LGPL2.1 license.

'''
This module defines the `ThreadTimer` class.

See its documentation for more info.
'''
# todo: daemonize?
# todo: kickass idea: make all timers use one thread that will sleep smartly
# to send all events correctly.

import threading
import time

import wx

from garlicsim_wx.general_misc import cute_base_timer


wxEVT_THREAD_TIMER = wx.NewEventType()
EVT_THREAD_TIMER = wx.PyEventBinder(wxEVT_THREAD_TIMER, 1)
'''Event saying that a `ThreadTimer` has fired.'''


class ThreadTimer(cute_base_timer.CuteBaseTimer):
   '''
   A timer for a wxPython app which runs on a different thread.
   
   This solved a problem of wxPython timers being late when the program is
   busy.
   '''
   
   n = 0
   '''The number of created thread timers.'''
   
   
   def __init__(self, parent):
      '''
      Construct the ThreadTimer.
      
      `parent` is the parent window.
      '''
      
      cute_base_timer.CuteBaseTimer.__init__(self, parent)
      
      self.parent = parent
      '''The parent window.'''
      
      ThreadTimer.n += 1
      self.wx_id = wx.NewId()
      '''The ID of this timer, given by wxPython.'''
      
      self.__init_thread()
      self.alive = False
      '''Flag saying whether this timer is running.'''

   def __init_thread(self):
      '''Create the thread.'''
      thread_name = ''.join(('Thread used by ThreadTimer no. ', str(self.n)))
      self.thread = Thread(self, name=thread_name)
      # Overwriting previous thread, so it'll get garbage-collected, hopefully
   
   def start(self, interval):
      '''Start the timer.'''
      if self.alive:
         self.stop()
      self.interval = interval
      self.alive = True
      self.thread.start()

   def stop(self):
      '''Stop the timer.'''
      self.alive = False
      self.thread.retired = True
      self.__init_thread()
   
   # Crutch for compatibilty with wx.Timer:
   Start = start
   Stop = stop
      
   def GetId(self):
      '''Get the wx ID of this timer.'''
      return self.wx_id

      
class Thread(threading.Thread):
   '''Thread used as a timer for wxPython programs.'''
   def __init__(self, parent, name):
      threading.Thread.__init__(self, name=name)
      self.parent = parent
      self.retired = False
      
   def run(self):
      '''Run the thread. Internal function.'''
      interval_in_seconds = self.parent.interval / 1000.0
      def sleep():
            time.sleep(interval_in_seconds)

      sleep()
      try:
         while self.parent.alive is True and self.retired is False:
            event = wx.PyEvent(self.parent.wx_id)
            event.SetEventType(wxEVT_THREAD_TIMER)
            wx.PostEvent(self.parent.parent, event)
            sleep()
      except:
         return # Just so it wouldn't raise an error when wx is shutting down